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Biomedical subjects

C E Baker

Publications and source records attributed to C E Baker.

5 recordsLinked to original sources
PubMed1992

Male infertility: role of transrectal US in diagnosis and management.

Ultrasound (US) has become crucial in the assessment of infertility of couples, in 50% of whom the male partner is responsible. Male infertility is caused by many diverse conditions, from reparable obstructive disorders to noncorrectable intrinsic testicular failure. During the past 4 years, a select group of 70 young infertile men with azoospermia or oligospermia and low ejaculate volume were examined with transrectal US. Twenty-six patients had congenital bilateral absence of the vas deferens, 11 had congenital unilateral absence of the vas deferens and contralateral obstructive pathology, 15 had additional abnormalities thought to be directly related to semen deficiencies, and 18 patients with other causes for semen deficiency and infertility had findings that were either normal or showed minor abnormalities. The delineation of congenital and obstructive abnormalities of the distal urogenital tract with transrectal US enables an accurate diagnosis of certain cases of male infertility and helps guide appropriate clinical and surgical management.

Adult↗
PubMed1991

Effect of pH of bupivacaine on duration of repeated sciatic nerve blocks in the albino rat. Local Anesthetics for Neuralgia Study Group.

Tachyphylaxis has been ascribed to tissue acidification after repeated injections of acidic local anesthetic solutions. We studied the effect of pH on the duration of action of bupivacaine to determine the validity of this proposed mechanism of tachyphylaxis by injecting bupivacaine solutions adjusted to pH 4.2 or 6.8 into a surgically implanted system created to permit in vivo irrigation of rat sciatic nerves with local anesthetic. Tachyphylaxis developed at both pH values. The results fail to support the acidification hypothesis as there was no statistically significant effect of a 400-fold difference in hydrogen ion concentration on the development of tachyphylaxis or the duration of motor dysfunction.

Anesthesia, Local↗
PubMed1975

Elimination of 137-Cs and 59-Fe and its relationship to metabolic rates of wild small rodents.

Elimination of 137-Cs and 59-Fe by three species of wild rodents was measured in laboratory and field experiments to determine whether excretion rates of these nuclides are influenced directly by general metabolic (CO-2 production) rates. Sigmodon hispidus and Peromyscus leucopus were used in both field and laboratory experiments, and Reithrodontomys humulis was investigated only in the laboratory. Final-component biological half-lives (Tb) of 59-Fe for Sigmodon averaged 108 days in winter, 144 days in spring, and means ranged from 176 to 242 days under various laboratory conditions (ambient temperature, cold-exposure, irradiation, and chemical metabolic inhibition); for Peromyscus, values were 50 days in winter 47 days in spring, and 289 days (at ambient temperature only) in the laboratory; for Reithrodontomys mean values ranged from 121 to 178 days at different laboratory treatment levels. Biological half-lives of final-component 137-Cs elimination for Sigmodon averaged 7.5 days in winter, 7.9 days in spring, and means ranged from 7.7 to 8.6 days at the different treatment levels in the laboratory. Laboratory mean values for Reithrodontomys ranged from 3.5 to 3.9 days. For Peromyscus, Tb values averaged 3.4 days in winter, 3.6 days in spring, and 3.5 days in the laboratory. The data suggested that elimination of 59-Fe is influenced by metabolic rates of rodents in the field, but laboratory experiments were unable to demonstrate any predictable relationship. Neither did the rate of final-component 137-Cs loss from rodents appear to be influenced by metabolic rate in the laboratory or in the field. However, final-component Y-axis intercept values of 137-Cs exhibited a linear correlation with metabolic rates, and equations were derived from these intercept values to predict metabolism in the field for two species: for Sigmodon, Daily Average CO-2 Production (ml/hr/g, STP) [5.24-0.9172 (log-ea)] [0.886]; and for Reithrodontomys, = [12.51-1.80 (log-ea)] [0.886].

Animals↗